tags/cscope for system headers

I love tags files for in coding, and enjoy using the tag feature in [vim]{tag/vim} as well as the derived tag-based completion. I do a lot of my development in the kernel, so all I usually have to do is put /usr/src/linux into my vim tags configuration.

Sometimes I have to do some user space hacking too, and I often forget all the names of glib and pthread library functions. Having a system wide tags file is very very useful. Below is a Makefile that I carry around with me and place in /usr/include to keep my system tags in sync.

$ cat /usr/include/Makefile all: cscope.out tags

    cscope.out: cscope.files
            cscope -P`pwd` -b

    cscope.files:
            find . -name '*.h' > cscope.files

    tags: cscope.files
            rm -f tags
            xargs -n100 ctags -a < cscope.files

In my vimrc, I just have a line that sucks that in:

    :set tags=./tags,tags,../tags,../../tags,../../../tags,../../../../tags,/usr/src/linux/tags,/usr/include/tags

… as well as multiple other directories. The first few just make sure that I can find my tags in the current project I happen to be in… irregardless of how many directories I have descended into the project tree.